From: iZsh <izsh@fail0verflow.com>
Date: Sat, 21 Jun 2014 22:26:38 +0000 (+0200)
Subject: New LF edge detection algorithm + lowpass filter
X-Git-Tag: v1.1.0~1^2~2
X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/3b2fee43ea7d9e08b7729d662d8d010ee0e2a2e3?hp=3b2fee43ea7d9e08b7729d662d8d010ee0e2a2e3

New LF edge detection algorithm + lowpass filter

This is a new LF edge detection algorithm for the FPGA.

- It uses a low-pass IIR filter to clean the signal
(see https://fail0verflow.com/blog/2014/proxmark3-fpga-iir-filter.html)
- The algorithm is able to detect consecutive peaks in the same
  direction
- It uses an envelope follower to dynamically adjust the peak thresholds
- The main threshold used in the envelope follower can be set from the ARM side

fpga/lf_edge_detect.v,
fpga/lp20khz_1MSa_iir_filter.v,
fpga/min_max_tracker.v: New file.

fpga/lo_edge_detect.v, fpga/fpga_lf.v: Modify accordingly.

armsrc/apps.h (FPGA_CMD_SET_USER_BYTE1,
FPGA_CMD_SET_EDGE_DETECT_THRESHOLD): New FPGA command.
fpga/fpga_lf.v: Modify accordingly/Add a 8bit user register.

fpga/fpga_lf.bit: Update accordingly.

fpga/tests: New directory for testbenches

fpga/tests/Makefile: New file. It compiles the testbenches
and runs all the tests by default (comparing with the golden output)

fpga/tests/tb_lp20khz_1MSa_iir_filter.v,
fpga/tests/tb_min_max_tracker.v,
fpga/tests/tb_lf_edge_detect.v: New testbenches

fpga/tests/plot_edgedetect.py: New script to plot the results from
the edge detection tests.

fpga/tests/tb_data: New directory for data and golden outputs
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